Experimental Study Of Laminaria Japonica Polysaccharides Action Against Human Nasopharyngeal Carcinoma

Objective Nasopharyngeal carcinoma (NPC) is a high incidence cancer ofhead and neck malignant tumors southern china,98%are poorly squamous cellcarcinoma. The comprehensive treatment of NPC is used mainly to radiotherapyand adjuvant by chemotherapy. Using conventional radiotherapy andchemotherapy, which have a strong killing effect, for nasopharyngeal carcinomacells, but the absence of selectivity play a role, caused serious injuries to normaltissue at the same time, leading to a lot of serious complications, which severelyaffected patients’ treatment and quality of life. Therefore, it is looking for a highefficiency and low toxicity of anticancer drugs from natural plants and animals,which can enhance anti-cancer effects of radiotherapy and chemotherapy,simultaneously which can reduce the damage of radiotherapy and chemotherapy,has become an important part study to the treatment of anticancer drugs andreduce the treatment of complications. Laminaria japonica polysaccharide (LJP)is a Polysaccharide, which contains a variety of water-soluble monosaccharidesand a sulfate group extracted from kelp heteropolysaccharide. Numerous studies have demonstrated LJP has a variety of biologically active polysaccharides, suchas anti-tumor, anti-mutagenic, enhance immunity, anti-radiation[1-4], etc.However, the role of research in the prevention and treatment of nasopharyngealhad few studies[5-7], just our group has preliminary experiments to explore itsmechanism of action. This study is further evidence of the LJP to variety ofhuman nasopharyngeal carcinoma cells in vitro inhibition and looking for LJPsensitive cell lines, and through the human nasopharyngeal carcinoma cell lineHONE1vivo inhibition studies, then to explore the mechanism of anti-NPCfrom the LJP.Methods The MTT assay was used to evaluate cell apoptosis induced bydifferent doses of LJP in vitro. The impact on apoptosis of HONE1cells wasfurther determined by using Hoechst33258fluorescence staining and themigration ability was examined by a scratch assay. We established a model ofsubcutaneous neoplasm in nude mouse by transplanting HONE1cells. Threeexperimental groups included low, moderate and high dose of LJP and controlgroup were designed. Cell features of the neoplasm and blood vesselendothelium in it as well as liver and kidney tissue of experimental mice wereobserved through transmission electron microscopy (TEM). The expression ofrelative genes such as Bax, Bcl-2, Caspase-3, Caspase-8, Caspase-9and VEGFwere assessed by Western blot analysis.Results MTT assays showed there was a significant dose and timedependent inhibition effect of LJP on NPC cell proliferation, but the impact onnormal nasopharyngeal epithelial cell was negligible. And the fluorescencestaining of HONE1cells found increasing cell numbers of karyopyknosis andkaryorrhexis. The inhibited cell migration ability was demonstrated by a scratchassay. TEM indicated that cancer cells and blood vessel endothelium cells in the neoplasm appeared to apoptosis, however, liver and kidney tissue was notinfluenced. Western blot analysis showed an increasing expression of Bax/Bcl-2,Caspase-3, Caspase-8and Caspase-9as the increasing dose of LJP (P<0.05),and the expression of VEGF reduced on the contrary (P<0.05).Conclusion LJP may have a specific anti-tumor effect on NPC given itsobvious inhibition to multiple NPC cell lines and weak effect on normal tissues.The mechanism might be promoting tumor cell apoptosis and inhibitingangiogenesis in tumor.